Wall plug



' March 12, 1946. M, D. GIBSON 2,396,501

WALL PLUG Filed Sept. 11, 1944 INVENTOR.

M D. /eso/v Patented Mar. 12, 1946 UNITED STATES PATENT OFFICE WALL PLUG Marshall D. Gibson, Webster Groves, Mo.

Application September 11, 1944, Serial No. 553,537

Claims.

This invention relates to expanslble wall plugs or shells, particularly for use in providing a support on a hollow or solid wall by which various objects may be suspended or attached to the wall. It is frequently found to be difficult to attach a hook, nail, screw, etc., to a hollow wall formed of plasterboard, wallboard. or the like, and the main object of my invention is to provide a plug or shell which can be used in walls of this type (which will not ordinarily retain screws or nails) and will securely hold a nail, hook, screw, etc., and give the maximum of support to an article suspended therefrom or attached thereto; and also, it is sometimes diificult to drive a nail or screw into a solid wall. Plugs have heretofore been used in walls, but, as far as I am aware, in the plugs previously used the expanding portion has been of hollow, tubular construction, the forming of which required considerable time, labor, and expense. The expanding portion of my plug, on the contrary, is formed of substantially flat members which can be stamped out or cut from small pieces of metal, for instance, scrap, thus permitting a ver considerable saving in time and material, and consequently in cost of production.

Still another object of my plug or shell is that it is securely held through frictional engagement to both sides of a hollow wall with which it is engaged, and an additional advantage is that it may be attached to the wall without the aid of an tool other than an ordinary screwdriver.

Fig. 1 is a plan view of my plug in blank form.

Fig. 2 is a side view of the form shown in Fig. 1.

Fig. 3 is a plan view of the plug in assembled form.

Fig. 4 is an end view of the plug shown in Fig, 3.

Fig. 5 is a side elevation of my plug as it appears when inserted in a wall.

Fig. 6 is a side elevation of the plug in locked position in a wall,

Fig. '7 is a plan view of a blank of my plug in modified form.

Fig. 8 is a side elevation of the form shown in Fig. 7, when assembled.

Fig. 9 is an end view of the form shown in Fig. 8. I

The preferred form of the invention comprises a strip of any suitable metal having a center section I and end sections 2, each end section 2 being approximately half as long as the center section I. At the junction points of the section I and the sections 2 short slits are cut transversely into the strip to form offsets 3, as shown in Fig. 1. The end portions 2 are scored approximately half their length at their marginal edges to facilitate bending and have each a transversely curved section 2', the extremities of the end sections 2 being slightly narrower than the curved sections 2 and substantially fiat.

On each side of the section I the marginal portion 4 which extends between the offsets 3 is substantially fiat, and the intermediate section 5 between the marginal portions 4 has a slight transverse curvature. At the center of the strip I an aperture 6 is punched out. This aperture is of such diameter as to extend between the marginal portions 4 and its walls are screw-threaded. The section I is slightly embossed outwardly as shown at I to weaken it, although said section ma be scored at any point to permit ready bending at any desired place.

I will now described the operation when the shell is to be applied to a hollow wall: A transverse bend is made in the strip l on either side of the aperture 6 and at a slight distance therefrom, as shown at B in Fig. 5, so that the strip is bent into an approximatel U-shaped element which forms the shell or plug, and the flat ends of the sections 2 are bent outwardly. A tubular shell 9, of proper size to enter a hole or aperture in which the U-shaped plug is to be driven, is slipped over the shell so that it is seated between the offsets 3 and the outturned, protruding ends 2, where it will be securely locked in position on the metal strip, the ofisets 3 acting as stop members for said tubular shell. The ends of the sections 2 protrude from said tubular shell as explained above, and these protruding ends form right angles at the point where they emerge irom the tubular shell 9,'as shown in Fi 4.

A hole is bored in the wall W and the plug or shell with the tubular shell 9 thereon is passed through said hole from the front, so that the tubular shell is positioned within the hole, the

latter being of such size that the tubular shell- 9 will slip therein, and theprotruding ends of the sections 2 lie substantially flat against the wall, as illustrated in Fig. 5. A screw 10 of suitthe screw is forced forward it brings with it the apertured end or the plug by virtue of the interengagement of the screwthreaded aperture 6 and the threads of the screw II, and as this forward movement continues the metal strip is bent outwardly at the weakened points 1 until these points contact and are firmly forced against the inner surface of the wall, at which time the plug has assumed the position shown in Fig. 6. The screw I I is then withdrawn through an unscrewing movement andthe plug or shell is ready for the reception of a hook, nail, screw, etc. When the plug or shell has been thus positioned in the wall, a screw, hook, etc., may be inserted therein to give support to an object which is to be secured to the wall and may be easily removed when desired.

From what has been said it will be obvious that when the plug or shell is to be used in a solid wall the principle of the invention is the same; that is to say, when the plug is inserted into a hole which has been bored in the wall and expansion pressure is applied, the strip I will bend outwardly at the weakened points 1 in the manner described above, which will bring thesepoints against the walls of the hole and force said points of the strip into firm, gripping contact therewith.

The degree of expansion of the plug in the solid wall will not be quite as great as in the hollow wall, but it is obvious that the same principle is applied and the same result attained, viz., the plug will be frictionally fixed to the wall to receive a screw, hook, or the like for supporting an object.

The plug or shell thus far described has but two members comprising sections I and 2, but it is to be understood that my invention may have three or more of such members, that is to say, as many expansion sections as may be desired. In Figs. 7, 8, and 9 I have illustrated a modification of my plug or shell having three of these members, each consisting of a section I and an extension 2' and having ofisets 3, a screwthreaded aperture 6" being punched out at the point where the sections I'- converge. This form of the invention has marginal portions I, curved sections and embossed points 1 corresponding to the elements 4, 5, and 1, respectively, in the preferred form of the invention, and has a similar tubular shell 8'.

In operation the procedure is similar to that employed with the preferred form: When the plug or shell has been placed in position in the 7 hole in the wall with the protruding ends of sections 2- lying substantially flat against the outer surface of the wall, the screw is inserted until its threads engage the threaded wall of the aperture 6- and the screwhead contacts firmly the bent back ends of the sections 2 As with the preferred form, the screwhead is then pried away from the ends 2, which causes the sections I to bend outwardly at the three weakened points l until they are forced firmly against the inner surface of the wall, after which the procedure is exactly the same as with the preferred form of the invention. The operation in a solid wall is the same, except that, as pointed out previously,

therewillbeasmallerdegreeoiexpansimofthe sections I'thaninthehollowwall.

I claim:

1. A wall plug or shell comprising a longitudinal member bent intermediate its length to form said shell or plug, and a tubular shell around the ends of said longitudinal member but spaced away from their extremities, the ends of said longitudinal member being bent away from each other, and means for weakening said longitudinal member at predetermined points so that said longitudinal member will expand outwardly when pressure is applied to the ends of said plug or shell. 1

2. A U-shaped wall plug or shell comprising a longitudinal member bent intermediate its ends to form U-shaped expansion strips, and a tubular shell surrounding said expansion strips near but spaced from their free ends, the free ends of said expansion strips being outwardly bent to form flanges, and the legs of said U-shaped plug or shell being embossed at predetermined points so that they will bulge outwardly when expanding pressure is applied to said flanges and to the U- bend of said plug or shell.

3. A U-shaped wall plug or shell comprising legs integrally formed of a longitudinal member, a tubular shell surrounding said legs near but spaced from their free ends, and means for retaining said encircling element in position, the free ends of said legs being outwardly bent to form flanges, and the legs of said U-shaped plug being slightly bent outwardly at predetermined point so that they will bulge outwardly when expanding pressure is applied to said flanges and to the U-bend of said plug, said plug being provided with means at its U-bend to permit the simultaneous application or expanding presure at both ends of said plug through the agency of a single tool.

4. A wall plug or shell comprising a plurality of members branching out from a central point and adapted to be bent upwardly from said point, and a tubular shell surrounding said members near but spaced from their free ends, the free ends of said members being outwardl bent to form flanges, said members being weakened at predetermined points so that they will bulge outwardly when expanding pressiue is applied to said flanges and to said central point.

5. A wall plug comprising a plurality of integrally formed members branching out from a central point and bent upwardly from said point, a tubular shell surrounding said members near but spaced from their free ends, and means for retaining said encircling element in the free ends of said members being outwardly bent to form flanges, said members being weakened at predetermined points so that they will bulge outwardly when expanding pressure is applied to said flanges and to said central point, and means at said central point to permit the simultaneous application of pressure at both ends of said plug through the agency of a single tool.

MARSHAIL D. GIBSON. 

